/*
 * Copyright (C) 2008 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.example.android.apis.graphics;

import com.example.android.apis.R;

import android.content.Context;
import android.graphics.*;
import android.os.Bundle;
import android.view.*;

public class Vertices extends GraphicsActivity {

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(new SampleView(this));
	}

	private static class SampleView extends View {
		private final Paint mPaint = new Paint();
		private final float[] mVerts = new float[10];
		private final float[] mTexs = new float[10];
		private final short[] mIndices = { 0, 1, 2, 3, 4, 1 };

		private final Matrix mMatrix = new Matrix();
		private final Matrix mInverse = new Matrix();

		private static void setXY(float[] array, int index, float x, float y) {
			array[index * 2 + 0] = x;
			array[index * 2 + 1] = y;
		}

		public SampleView(Context context) {
			super(context);
			setFocusable(true);

			Bitmap bm = BitmapFactory.decodeResource(getResources(),
					R.drawable.beach);
			Shader s = new BitmapShader(bm, Shader.TileMode.CLAMP,
					Shader.TileMode.CLAMP);
			mPaint.setShader(s);

			float w = bm.getWidth();
			float h = bm.getHeight();
			// construct our mesh
			setXY(mTexs, 0, w / 2, h / 2);
			setXY(mTexs, 1, 0, 0);
			setXY(mTexs, 2, w, 0);
			setXY(mTexs, 3, w, h);
			setXY(mTexs, 4, 0, h);

			setXY(mVerts, 0, w / 2, h / 2);
			setXY(mVerts, 1, 0, 0);
			setXY(mVerts, 2, w, 0);
			setXY(mVerts, 3, w, h);
			setXY(mVerts, 4, 0, h);

			mMatrix.setScale(0.8f, 0.8f);
			mMatrix.preTranslate(20, 20);
			mMatrix.invert(mInverse);
		}

		@Override
		protected void onDraw(Canvas canvas) {
			canvas.drawColor(0xFFCCCCCC);
			canvas.save();
			canvas.concat(mMatrix);

			canvas.drawVertices(Canvas.VertexMode.TRIANGLE_FAN, 10, mVerts, 0,
					mTexs, 0, null, 0, null, 0, 0, mPaint);

			canvas.translate(0, 240);
			canvas.drawVertices(Canvas.VertexMode.TRIANGLE_FAN, 10, mVerts, 0,
					mTexs, 0, null, 0, mIndices, 0, 6, mPaint);

			canvas.restore();
		}

		@Override
		public boolean onTouchEvent(MotionEvent event) {
			float[] pt = { event.getX(), event.getY() };
			mInverse.mapPoints(pt);
			setXY(mVerts, 0, pt[0], pt[1]);
			invalidate();
			return true;
		}

	}
}
